ARM讀取DS1302匯編程序

ID:113276 · 發(fā)表于 2016-4-10 17:33

GPACON          EQU          0x56000000

GPADAT          EQU          0x56000004
GPAUP             EQU          0x56000008
                     EXPORT xmain
                     AREA Init,CODE,READONLY
                     ENTRY
xmain
                     ldr r0,=GPACON
ldr r1,[r0]
                     bic r1,r1,#0xff
bic r1,r1,#0x1f00
                     str r1,[r0] ;A=out
mov r6,#0x53
BL R1302
B xmain
;====================================
R1302 mov r7,#0
ldr r0,=GPADAT
ldr r1,[r0]
ORR r1,r1,#0x400
str r1,[r0]    ;rst=1
;========
lp and r8,r6,#0x01
cmp r8,#0x01
bne dd2
orr r1,r1,#0x1000
B dd1
dd2 bic r1,r1,#0x1000
dd1 str r1,[r0]
                     ror r6,r6,#1
orr r1,r1,#0x800
str r1,[r0]
add r7,r7,#1
bic r1,r1,#0x800
str r1,[r0]
                     cmp r7,#8
bne lp
;========
ldr r0,=GPACON
ldr r1,[r0]
orr r1,r1,#0x1000
str r1,[r0]
mov r7,#0
mov r6,#0
mov r8,#0
ldr r0,=GPADAT

gg1 ldr r8,[r0]
and r8,r8,#0x1000
cmp r8,#0x1000
bne gg2
orr r6,r6,#1
gg2 LSL r6,r6,#1
orr r1,r1,#0x800
nop
bic r1,r1,#0x800
add r7,r7,#1
cmp r7,#8
bne gg1
mov pc,lr
END

帳號(hào)		自動(dòng)登錄	找回密碼
密碼			立即注冊(cè)